Failure Case Library

Real lab failures, root causes, and fixes — curated and bilingually annotated by our team.

All Techniques (7) Nucleic Acid Quantification (9) Lipid Transfection (8) End-point PCR Primers (9) Cell Culture (Contamination) (7) PCR (Sigma Guide) (12) Flow Cytometry (Controls) (8) PCR / qPCR Plastics (9) PCR (Invitrogen Guide) (8) Cell Culture (Precipitates) (6) Cell Culture (Cell Death) (8) ELISA (Sigma Guide) (6) PCR / RT-PCR Amplification Problems (5) Flow Cytometry (Paraformaldehyde Fixation) (14) Flow Cytometry (Sample Considerations) (14) ELISA (R&D Guide) (10) Western Blot Immunodetection (19) Flow Cytometry (CST Guide) (8) Immunohistochemistry (CST Guide) (14) Immunoprecipitation (CST Guide) (14) ChIP (CST Guide) (8) ELISA Development (9) Western Blot (Sigma Protocol) (8) IP-Western Blot (6) Western Blot (CST Guide) (8) Flow Cytometry (Fixation Buffers) (7) Flow Cytometry (Isotype Controls) (7) Flow Cytometry (Fixation & Permeabilization) (9) Flow Cytometry (Fc Blocking) (7) Flow Cytometry (Compensation) (7) Flow Cytometry (Autofluorescence) (7) Flow Cytometry (Troubleshooting) (8) Tissue Imaging (Autofluorescence) (9) ELISPOT (8) Immunoprecipitation (Protein Obstruction) (1) Immunoprecipitation (No Protein Detected) (5) Immunoprecipitation (High Background) (8) Immunoprecipitation (High Antibody Elution) (1) Immunohistochemistry (No Staining) (9) Immunohistochemistry (High Background) (9) ChIP (PCR Amplification Problems) (4) ChIP (Low Signal) (8) ChIP (Low Resolution with High Background) (6) ChIP (High Background) (1) Western Blot (Blue Background) (1) Western Blot (Unusual Gel Band Appearance) (3) Western Blot (Unexpected Multiple Bands) (7) Western Blot (Misshapen / Uneven Bands) (5) Western Blot (Bands at Wrong MW) (5) Western Blot (Detection Problems) (7) Western Blot (Weak / No Signal) (6) ELISA (Standard Curve Fit Problems) (6) ELISA (Inconsistent Results / High CV) (6) ELISA (High Background) (8) ELISA (Signal Problems) (11) ELISA (Competitive) (18) Cell-free DNA Extraction (8) Bacterial rRNA Depletion (4) RNA Depletion for RNA-seq (7) LAMP (Loop-mediated Isothermal Amplification) (7) HMW DNA Extraction (Monarch) (7) NGS Library Preparation (NEBNext Ultra II) (7) RNA Cleanup (4) DNA Cleanup & Plasmid Purification (7) PCR (Polymerase Chain Reaction) (26) Restriction Enzyme Digest (13) Western Blot (9) Immunohistochemistry (IHC) (6) Colony Formation Assay (10) Transwell Migration / Invasion Assay (5) qPCR (RT-qPCR) (5) Transfection (8) Plasmid Construction (1) Sanger Sequencing (2) Plasmid Mini-prep (1) Plasmid Construction (Double Digest) (1) Protein Extraction (4) Transfection (Co-transfection) (1) Transfection (siRNA Knockdown) (1) CCK-8 Cell Viability Assay (5) Wound Healing Assay (5)
DNA Cleanup & Plasmid Purification critical

No DNA Recovered from Plasmid Miniprep

No detectable plasmid DNA is recovered after miniprep purification. Column elution yields no nucleic acid by spectrophotometry or gel electrophoresis.

💡 4 causes ✓ 4 fixes
DNA Cleanup & Plasmid Purification severe

Low Plasmid Yield Due to Incomplete Lysis

Plasmid miniprep yields are significantly below expected levels. A260/280 ratio may be normal but total DNA concentration is low.

💡 5 causes ✓ 5 fixes
DNA Cleanup & Plasmid Purification moderate

Low DNA Yield from Gel Extraction or PCR Cleanup Due to Incomplete Elution

DNA recovery from gel extraction or PCR cleanup is lower than expected based on input amount. Some DNA likely remains bound to column.

💡 4 causes ✓ 4 fixes
DNA Cleanup & Plasmid Purification severe

Low Gel Extraction Yield Due to Improper Gel Dissolution

DNA yield from gel extraction is poor. Undissolved agarose particles may be visible or column flow is impeded.

💡 4 causes ✓ 4 fixes
DNA Cleanup & Plasmid Purification critical

No DNA Recovered from Gel Extraction or PCR Cleanup

No DNA is recovered after gel extraction or PCR cleanup procedures. Elution yields no measurable nucleic acid.

💡 3 causes ✓ 3 fixes
DNA Cleanup & Plasmid Purification severe

Low Plasmid Quality Due to Degradation or Denaturation

Plasmid DNA shows smearing on gel, poor A260/280 ratio, or fails in downstream applications despite adequate concentration. Multiple bands or reduced supercoiled form may be visible.

💡 5 causes ✓ 5 fixes
DNA Cleanup & Plasmid Purification moderate

Low DNA Performance in Downstream Applications Due to Contaminants

Purified DNA fails or performs poorly in downstream applications (transformation, restriction digestion, PCR, sequencing) despite acceptable concentration and A260/280 ratio.

💡 6 causes ✓ 6 fixes